Alzheimer’s & Dementia | August 3, 2023

Pamela C. L. Ferreira, Joseph Therriault, Cécile Tissot, João Pedro Ferrari-Souza, Andréa L. Benedet, Guilherme Povala, Bruna Bellaver, Douglas T. Leffa, Wagner S. Brum, Firoza Z. Lussier, Gleb Bezgin, Stijn Servaes, Marie Vermeiren, Arthur C. Macedo, Arlec Cabrera, Jenna Stevenson, Gallen Triana-Baltzer, Hartmuth Kolb, Nesrine Rahmouni, William E. Klunk, Oscar L. Lopez, Victor L. Villemagne, Ann Cohen, Dana L. Tudorascu, Eduardo R. Zimmer, Thomas K. Karikari, Nicholas J. Ashton, Henrik Zetterberg, Kaj Blennow, Serge Gauthier, Pedro Rosa-Neto, Tharick A. Pascoal

Alzheimer’s Dement. 2023

https://doi.org/10.1002/alz.13393

Abstract

INTRODUCTION

Phosphorylated tau (p-tau) biomarkers have been recently proposed to represent brain amyloid-β (Aβ) pathology. Here, we evaluated the plasma biomarkers’ contribution beyond the information provided by demographics (age and sex) to identify Aβ and tau pathologies in individuals segregated as cognitively unimpaired (CU) and impaired (CI).

METHODS

We assessed 138 CU and 87 CI with available plasma p-tau231, 217⁺, and 181, Aβ42/40, GFAP and Aβ- and tau-PET.

RESULTS

In CU, only plasma p-tau231 and p-tau217⁺ significantly improved the performance of the demographics in detecting Aβ-PET positivity, while no plasma biomarker provided additional information to identify tau-PET positivity. In CI, p-tau217⁺ and GFAP significantly contributed to demographics to identify both Aβ-PET and tau-PET positivity, while p-tau231 only provided additional information to identify tau-PET positivity.

DISCUSSION

Our results support plasma p-tau231 and p-tau217⁺ as state markers of early Aβ deposition, but in later disease stages they inform on tau tangle accumulation.